Audi a4 2000 model b5 apt engine

[luggs2008]

Hi all,

The coolant temperature sensor located at the rear of the cylinder head, that is fitted into a plastic recess part of a coolant hose, could someone confirm its function(s) please?

From the information I have gathered on my model fitted with the apt engine, I believe it controls the temperature gauge on the dash clocks, and it controls fuel modulation on cold start ie controls the fuel injection, am I correct could someone please confirm this? thanks.

[Trevor]

Hi Michael....welcome to the Forum

The Coolant Temperature Sensor (CTS) measures the temperature of the coolant at all times and is constantly referenced by the Engine Management System (EMS) and Instrumentation to determine the correct fuel quantity, ignition timing, fans and just about anything else that needs to know how hot the engine is. There is sometimes only one wire, which would indicate that this sensor is for the gauges only, or two/three wires which would indicate the sensor is being used for EMS and gauges...and anything else needing the temp reading.

Hope this clarifies it for you?

Cheers   Trevor

[luggs2008]

Hi Trevor,

Thanks for the reply, yes it answers my question thanks, just ordered new cts only flagged up briefly on diagnostics i had other running isssues which i have addressed but it was this final hurdle to nail so hopefully be back on the road tommorrow